核燃料包壳是反应堆安全的第一道屏障,对核电站的稳定运行具有重要作用,但是它却工作在高温、高压和高辐射的环境中,这对核燃料包壳材料提出苛刻的要求。为了保证包壳在整个服役期间的完整性,压水堆燃料组件设计准则中,对包壳在役期间的应力强度、环向应变和轴向伸长等都提出了明确的要求。因此,为保证包壳在反应堆中具有良好的机械性能,需充分了解包壳管的高温机械性能。 Nuclear fuel cladding is the first barrier to reactor safety and plays an important role in the stable operation of nuclear power plants. However, it works in high temperature, high pressure and high radiation environment, which puts harsh demands on nuclear fuel cladding material. In order to ensure the integrity of the cladding during service, the PWR fuel assembly design guidelines set clear requirements on the stress strength, circumferential strain and axial elongation of the cladding during service. Therefore, in order to ensure the cladding has good mechanical properties in the reactor, it is necessary to fully understand the high temperature mechanical properties of the cladding tube.